Launch Report, 13 September 1997

WOOSH holds monthly launches on the second Saturday of the month at the Milwaukee County grounds - near the intersection of Highway 45 and Wisconsin Avenue.

Jeanne (my wife) and I got to the park just before 2:00 after attending my company's family picnic at the Milwaukee County Zoo. Kurt, Mark and Ken were already there, so I got set up and joined in.

Kurt showed off a beautifully finished Astron Midget (built from JimZ plans). I hope he brings it to the next meeting so I can look at it a bit more closely. I enjoyed everyone's launches (Mark's Intercepter and payload birds and Kurt's Gemini-Titan in particular), but only kept track of my own. That said, here's what I did this month.

I brought along four models -- a virgin Estes SR-71, my Big Bertha clone (finally, a launch for it ), an Estes Nighthawk and my Yankee Clipper.

My first launch today was my virgin Big Bertha clone on an Estes B6-2, using a 4"x40" crepe paper streamer for recovery. Launch was very nice, very straight and plenty high and recovery was excellent. The nose cone led the way down with the body tube coming down in a horizontal attitude. This rocket looks like a winner! I can see why there have been a lot of votes for this one as people's favorite rocket on RMR.

Next, I decided to try the Bertha clone with a CMR Manta parasite glider on a B6-2. This time up we had a problem with the glider getting tangled in the shock cord, but everything came down without any damage.

My Estes Nighthawk on an A8-3 went up next. It went up very well, but I've got to adjust the power pod fins. There was a big arc on this launch, but when the pod ejected at 100+ feet the glider flew fine. The only negative is (again, like at ECOF) that the glide circle is a bit tight. I'm going to have to fiddle with the glider some more to try to open up the circle a bit.

I needed to practice (test) with the Apogee motors that I plan to use in my 4-A cluster, so I loaded an A2-7 into my Yankee Clipper. I figured the rocket *might* be a little heavy for the delay, but after considering how well it flew at ECOF, 97 I decided to give it a try anyway. I used the supplied Power-Punch® ignitor to start the motor. The first attempt to launch just sat on the pad. After the requisite 60 second wait, I removed the rocket from the pad and checked the motor and igniter. It looked like the ignitor may have been shorting itself, since the pyrogen showed no indication of having burned, so I spread the legs of the ignitor a little wider, reinstalled it and gave it a second try.

On the second attempt, it took a *long* time before ignition (maybe 5 seconds? I wonder if it might still have been shorted just short of the pyrogen), but it did ignite and launched beautifully. The Clipper arced slightly into the breeze and was coasting wonderfully (1, 2, 3...), arced over at apogee (4, 5...) and headed for the ground. It impacted at about 9 seconds, sinking the nose cone a good inch into the ground and severely crimping the body tube just in front of the engine mount. There it sat, stuck in the ground and smoking furiously (tracking charge), for a couple seconds before the ejection charge finally seperated the body and nose cone. *POOT* Think of Wile E. Coyote and a missile from ACME <VBG>. A long delay will probably be a good thing for the 4-A cluster, but was way too much for the Clipper. Does Apogee give bonus delays, too?<G>

I'm not sure if this is rebuildable, since the crimped tube is so close to the motor retainer, but I'll see what I can do with it.

I just got some paint on the SR-71 this morning before we headed for the company picnic. I decided to give it its first launch on a B6-2. Very nice liftoff and ejection, but the chute didn't open. Fortunately, the SR-71 is pretty tough and there was no damage. The nose cone did embed about 1/4" into the [soft] ground, but no damage. I'll do some investigation and apply the decals before the next launch.

I decided to give the Bertha clone w/ Manta parasite another try on a B6-2. This time it worked great! I wish I had timed the glide, because it took about five good-sized circles (with a slight stall each time it headed upwind) before it finally touched down. Great!

Launch of my Bertha clone. (7k)
Photo ©1977 by Ken Walsh
Used with permission
 Finally, I read on RMR that a Big Bertha on a small motor can be a good entry for spot landing, so I decided to try my clone on a 1/2A6-2. I wasn't sure just what to expect, but it went better than I feared, even if not as well as I hoped. We decided to define a soccer goal about 60 feet away from the pads as the 'spot' and I angled the launch rod toward it (well within 30 degrees from vertical). On ignition, the Bertha *lept* off the pad (Ken got a nice shot of it with his digital camera, see image at left) to an altitude of maybe 20 feet. It *did* get the streamer ejected *BEFORE* ground contact <G>. Total ground distance covered was MAYBE 15 feet.

Hummmmm...

We may have to use *just* a little more power next time <VBG>

All in all, 7 launches and even with the loss of the Yankee Clipper (rebuildable, I think), a fun day.
As a side note, I REALLY appreciated the kids doing recovery at the launch today. A couple of the models drifted a ways away and I liked not having to shag the models back myself. They treated the models carefully and during the course of the launch were *very* well behaved. Thanks you, Kurt, Mark and Ken, for bringing them along!

Rognlies of Racine
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Last Updated: 18 September 1997
Author: Alan Rognlie
Email: arrognli@execpc.com
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unless otherwise noted, all images are copyright © 1997 by Jeanne Rognlie - all rights reserved